Bicycle hydraulic operating system

ABSTRACT

A bicycle hydraulic operating system is basically provided with first and second actuating devices and a hydraulic operated device. The first actuating device includes a first operating member, a first master cylinder and a first master piston. The first master piston moves in the first master cylinder in response to operation of the first operating member. The second actuating device includes a second operating member, a second master cylinder and a second master piston. The second master piston moves in the second master cylinder in response to operation of the second operating member. The hydraulic operated device includes a slave cylinder and a slave piston that is movably arranged in the slave cylinder. The slave cylinder has a slave fluid port that is connected to first and second fluid ports of the first and second master cylinders. Operation of either of the first and second operating members moves the slave piston.

BACKGROUND

1. Field of the Invention

This invention generally relates to a bicycle hydraulic operatingsystem. More specifically, the present invention relates to a bicyclehydraulic operating system having first and second actuating devicesthat operate a single hydraulic operated device.

2. Background Information

Recently, hydraulic brake systems are for used in bicycles. Thehydraulic brake system for a bicycle typically has a brake lever (e.g.,an actuating device) that is fluidly connected to a brake caliper (e.g.,a hydraulic operated device) by a hydraulic brake hose. The brakecaliper is hydraulically controlled by hydraulic fluid flowing throughthe hydraulic brake hose in response to an operation of the brake lever.In particular, the operation of the brake lever forces hydraulic fluidthrough the hydraulic brake hose to the brake caliper. The hydraulicfluid then moves one of more pistons to cause the brake pads to squeezea brake rotor that is attached to a hub of a bicycle wheel.

SUMMARY

Generally, the present disclosure is directed to various features of abicycle hydraulic operating system. In one feature, a hydraulicoperating system is provided in which having first and second actuatingdevices operate a single hydraulic operated device.

In view of the state of the known technology and in accordance with afirst aspect of the present disclosure, a bicycle hydraulic operatingsystem is provided that basically comprises a first actuating device, asecond actuating device and a hydraulic operated device. The firstactuating device includes a first operating member, a first mastercylinder and a first master piston. The first master cylinder has afirst fluid port. The first master piston is movably arranged in thefirst master cylinder in response to an operation of the first operatingmember. The second actuating device includes a second operating member,a second master cylinder and a second master piston. The second mastercylinder has a second fluid port. The second master piston is movablyarranged in the second master cylinder in response to an operation ofthe second operating member. The hydraulic operated device includes aslave cylinder and a slave piston. The slave piston is movably arrangedin the slave cylinder. The slave cylinder has a slave fluid port fluidlyconnected to the first and second fluid ports of the first and secondmaster cylinders such that the operation of the first operating membermoves the slave piston and such that the operation of the secondoperating member moves the slave piston.

In accordance with a second aspect of the present invention, the bicyclehydraulic operating system according to the first aspect is configuredso that at least one of the first and second actuating devices has afluid reservoir.

In accordance with a third aspect of the present invention, the bicyclehydraulic operating system according to the first aspect is configuredso that one of the first and second actuating devices has a fluidreservoir and the other of the first and second actuating devices has noreservoir.

In accordance with a fourth aspect of the present invention, the bicyclehydraulic operating system according to the first aspect is configuredso that the first operating member includes a first lever. The firstactuating device is configured to displace hydraulic fluid with a firstamount as the first lever is pivoted with a first stroke.

The second operating member includes a second lever. The secondactuating device is configured to displace hydraulic fluid with a secondamount differing from the first amount as the second lever is pivotedwith a second stroke being same as the first stroke.

In accordance with a fifth aspect of the present invention, the bicyclehydraulic operating system according to the first aspect furthercomprises a switching device selectively coupling one of the first andsecond master cylinders to the hydraulic operated device.

In accordance with a sixth aspect of the present invention, the bicyclehydraulic operating system according to the fifth aspect is configuredso that at least one of the first and second actuating devices has afluid reservoir.

In accordance with a seventh aspect of the present invention, thebicycle hydraulic operating system according to the fifth aspect isconfigured so that the switching device includes a housing having afirst opening fluidly connected to the first fluid port of the firstmaster cylinder, a second opening fluidly connected to the second fluidport of the second master cylinder and a third opening fluidly connectedto the slave fluid port of the slave cylinder. The switching devicefurther includes a movable member movably mounted in the housing toblock the second opening in response to the operation of the firstoperating member and to block the first opening in response to theoperation of the second operating member.

In accordance with an eighth aspect of the present invention, thebicycle hydraulic operating system according to the first aspect isconfigured so that the second actuating device has no fluid reservoir,and the first fluid port of the first actuating device is fluidlyconnected to the second master cylinder of the second actuating deviceat a point upstream of the second fluid port with respect to a flow ofhydraulic fluid towards the hydraulic operated device.

In accordance with a ninth aspect of the present invention, the bicyclehydraulic operating system according to the eighth aspect is configuredso that the second master cylinder of the second actuating devicefurther includes a connecting port and the connecting port selectivelyand fluidly connects the first fluid port of the first actuating deviceto the slave fluid port of the hydraulic operated device in accordancewith a position of the second master piston of the second actuatingdevice.

In accordance with a tenth aspect of the present invention, the bicyclehydraulic operating system according to the ninth aspect is configuredso that the connecting port comprises a first portion and a secondportion, the first portion selectively and fluidly connects the firstfluid port to the slave fluid port in accordance with the position ofthe second master piston, and the second portion is in fluidcommunication with a space between an outer surface of the second masterpiston and an inner surface of the second master cylinder.

In accordance with an eleventh aspect of the present invention, thebicycle hydraulic operating system according to the eighth aspect isconfigured so that the second actuating device further includes aconnecting port and a push rod. The push rod operatively connects thesecond operating member to the second master piston. The second masterpiston has a fluid passage that fluidly connects the connecting port tothe second fluid port through the second master piston and isselectively blocked by the push rod in response to the operation of thesecond operating member.

In accordance with a twelfth aspect of the present invention, thebicycle hydraulic operating system according to the first aspect isconfigured so that the first actuating device includes a bracket and asecuring member. The bracket has a proximal end portion, a distal endportion and a gripping portion that is arranged between the proximal endportion and the distal end portion. The securing member is provided onthe proximal end portion of the bracket for securing the bracket to ahandlebar. The first operating member is pivotally attached to thedistal end portion.

In accordance with a thirteenth aspect of the present invention, thebicycle hydraulic operating system according to the twelfth aspect isconfigured so that the second actuating device is configured such thatthe second operating member extends in a lateral direction in a statewhere the second actuating deceive is mounted to the handlebar.

In accordance with a fourteenth aspect of the present invention, thebicycle hydraulic operating system according to the first aspect isconfigured so that the hydraulic operated device comprises a hydraulicbraking device.

In accordance with a fifteenth aspect of the present invention, thebicycle hydraulic operating system according to the fourteenth aspect isconfigured so that the hydraulic operated device comprises the hydraulicdisc brake caliper.

Also other objects, features, aspects and advantages of the disclosedhydraulic operating system will become apparent to those skilled in theart from the following detailed description, which, taken in conjunctionwith the annexed drawings, discloses several embodiments of thehydraulic operating system.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the attached drawings which form a part of thisoriginal disclosure:

FIG. 1 is a schematic perspective view of a bicycle hydraulic operatingsystem in accordance with a first illustrated embodiment;

FIG. 2 is a schematic view of the bicycle hydraulic operating systemillustrated in FIG. 1 with selected components shown in cross sectionand the first and second actuating devices in rest positions ornon-operated positions and the switching device in a center or neutralposition;

FIG. 3 is an enlarged schematic elevational view of the first actuatingdevice and the switching device of the bicycle hydraulic operatingsystem illustrated in FIG. 2 with the first lever of the first actuatingdevice moved to a partially operated position and the switching devicemoved to a first position;

FIG. 4 is an enlarged schematic elevational view of the second actuatingdevice and the switching device of the bicycle hydraulic operatingsystem illustrated in FIG. 2 with the second lever of the secondactuating device moved to a partially operated position and theswitching device moved to in a second position;

FIG. 5 is a schematic view of a bicycle hydraulic operating system inaccordance with a second illustrated embodiment showing selectedcomponents in cross section and the first and second actuating devicesin rest positions or non-operated positions and the switching device ina center or neutral position;

FIG. 6 is a schematic perspective view of a bicycle hydraulic operatingsystem in accordance with a third illustrated embodiment;

FIG. 7 is a schematic view of the bicycle hydraulic operating systemillustrated in FIG. 6 with selected components shown in cross sectionand the first and second actuating devices in rest positions;

FIG. 8 is a partial cross sectional view of the second actuating deviceof the bicycle hydraulic operating system illustrated in FIGS. 6 and 7with the piston of the second actuating device in a rest position or anon-operated position;

FIG. 9 is a partial cross sectional view, similar to FIG. 8, of thesecond actuating device of the bicycle hydraulic operating systemillustrated in FIGS. 6 and 7, but with the piston of the secondactuating device in an operated position;

FIG. 10 is a schematic view of a bicycle hydraulic operating system inaccordance with a fourth illustrated embodiment with selected componentsshown in cross section and the first and second actuating devices inrest positions;

FIG. 11 is a schematic perspective view of a bicycle hydraulic operatingsystem in accordance with a fifth illustrated embodiment;

FIG. 12 is a partial cross sectional view of the second actuating deviceof FIG. 11 with the piston of the second actuating device in a restposition or a non-operated position;

FIG. 13 is a partial cross sectional view, similar to FIG. 12, of thesecond actuating device, but with a push rod partially moved to block afluid passage of a second master piston; and

FIG. 14 is a partial cross sectional view, similar to FIGS. 12 and 13,of the second actuating device, but with a push rod fully moved tooperate the disc brake caliper (i.e., a hydraulic operated device).

DETAILED DESCRIPTION OF EMBODIMENTS

Selected embodiments will now be explained with reference to thedrawings. It will be apparent to those skilled in the bicycle field fromthis disclosure that the following descriptions of the embodiments areprovided for illustration only and not for the purpose of limiting theinvention as defined by the appended claims and their equivalents.

Referring initially to FIGS. 1 to 4, a portion of a bicycle 10 isillustrated that is equipped with a bicycle hydraulic operating system12 in accordance with a first embodiment. Here, in the first embodiment,the bicycle hydraulic operating system 12 basically comprises a firstactuating device 14, a second actuating device 16 and a hydraulicoperated device 18. Both of the first and second actuating devices 14and 16 are in fluid communication with the hydraulic operated device 18.In this way, the rider can actuate the hydraulic operated device 18using either one of the first and second actuating devices 14 and 16.Here, in the first embodiment, the bicycle hydraulic operating system 12further comprises a switching device 20 that selectively couples one ofthe first and second actuating devices 14 and 16 to the hydraulicoperated device 18. The first actuating device 14 is fluidly connectedto the switching device 20 by a first hydraulic line or hose 21. Thesecond actuating device 16 is fluidly connected to the switching device20 by a second hydraulic line 22. The switching device 20 is fluidlyconnected to the hydraulic operated device 18 by a third hydraulic line23.

Here, as seen in FIG. 1, the first and second actuating devices 14 and16 are mounted to a drop handlebar 24. More specifically, the drophandlebar 24 has a pair of curved sections 24 a (only one shown) and astraight section 24 b that interconnects the curved sections 24 a. Thefirst actuating device 14 is mounted to one of the curved sections 24 a.The second actuating device 16 is mounted to the straight section 24 b.In this way, the rider can operate the first actuating device 14 fromthe curved section 24 a, and operate the second actuating device 16 fromthe straight section 24 b.

As illustrated in FIGS. 1 to 4, the first and second actuating devices14 and 16 are a right hand side hydraulic component actuating devicethat are operated by the rider's right hand to actuate the hydraulicoperated device 18. It will be apparent to those skilled in the bicyclefield that the configuration of the first and second actuating devices14 and 16 can be adapted to a left hand side hydraulic operating systemthat is operated by the rider's left hand.

The first actuating device 14 is specifically designed for use on thecurved section 24 a of the drop handlebar 24. As explained below, thefirst actuating device 14 includes both a braking function and ashifting function in a single unit. In other words, the first actuatingdevice 14 is a bicycle brake/shift device, which is also known as abicycle brifter. In other words, as used herein, a bicycle brifter is adevice that includes both a braking function and a shifting function ina single unit that is mounted to the bicycle. Also as used herein, adrop handlebar brifter is a device that is specifically configured to bemounted to the curved section 24 a of the drop handlebar 24, asillustrated in FIG. 1, and that includes both braking and shiftingfunctions in a single unit. However, it will be apparent to thoseskilled in the bicycle field from this disclosure that the shiftingfunction could be eliminated from the first actuating device 14 ifneeded and/or desired.

As illustrated in FIGS. 1 to 3, the first actuating device 14 includes adrop handlebar bracket 30 (hereinafter referred as the bracket) having aproximal end portion 32, a distal end portion 34 and a gripping portion36. The gripping portion 36 is arranged between the proximal end portion32 and the distal end portion 34. Here, as illustrated in FIGS. 2 and 3,the bracket 30 includes a main body 30 a and a hydraulic unit 30 b. Themain body 30 a is typically made of a suitable material such as a hardplastic material, and forms a majority of the gripping portion 36. Thehydraulic unit 30 b is typically made of a metallic material, and isattached to the main body 30 a. The hydraulic unit 30 b is detachablefrom the main body 30 a by a bolt 30 c. The main body 30 a and thehydraulic unit 30 b are constructed as shown in U.S. Patent ApplicationPublication No. 2013/0255239 A1 (assigned to Shimano, Inc.).

Although not shown, the gripping portion 36 can have removable panels asneeded and/or desired. For example, the gripping portion 36 can includean outer panel for accessing an electronic circuit board installedwithin the gripping portion 36. The proximal end portion 32 has a curvedsurface 32 a (FIG. 3), which mates with the curved section 24 a of thedrop handlebar 24 when in the installed position. The distal end portion34 protrudes upwardly with respect to the gripping portion 36 to definea pommel portion of the bracket 30. The distal end portion 34 (i.e., thepommel portion) is located at a forward free end of the bracket 30.

As illustrated in FIG. 1, a grip hood or cover 38 is stretched over atleast the gripping portion 32 and the pommel portion 34 to provide acushion to the gripping portion 32 of the bracket 30 and the distal endportion 34 (i.e., the pommel portion) to provide an attractiveappearance and a comfortable feeling for the rider's hand. Typically,the grip cover 38 is made of elastic material such as rubber.

As illustrated in FIG. 3, the first actuating device 14 further includesa securing member 40 that is attached to the proximal end portion 32 ofthe bracket 30. The securing member 40 releasably secures the bracket 30to the curved section 24 a of the drop handlebar 24. The securing member40 basically includes a band part 40 a, a first fastener part 40 b, anda second fastener part 40 c. The second fastener part 40 c extends fromthe band part. The first fastener part 40 b is screwed onto the secondfastener part 40 c. The first fastener part 40 b and the second fastenerpart 40 c are located in a hole of the proximal end portion 32. In thisway, a head of the first fastener part 40 b applies a first force on theproximal end portion 32 and the second fastener part 40 c applies asecond force on the band part 40 a when the first fastener part 40 b isscrewed onto the second fastener part 40 c. Thus, by tightening thefirst fastener part 40 b, the band part 40 a is moved toward theproximal end portion 32 such that the curved section 24 a of the drophandlebar 24 is squeezed between the band portion 40 a and the curvedsurface 32 a of the proximal end portion 32. It will be apparent tothose skilled in the bicycle field that the securing member 40 that isnot limited to the illustrated mechanism, but rather other suitableattachment mechanisms can be used as needed and/or desired.

The first actuating device 14 further includes a first operating member42, a first master cylinder 44 and a first master piston 46. In thisfirst embodiment, the first actuating device 14 has a fluid reservoir48. Thus, in this first embodiment, the first actuating device 14 isconstructed as an open type hydraulic device. Basically, an operation ofthe first operating member 42 moves the first master piston 46 withinthe first master cylinder 44 to cause displacement of hydraulic fluidfrom the first master cylinder 44 to actuate the hydraulic operateddevice 18 via the switching device 20.

The first operating member 42 is pivotally attached to the distal endportion 34 of the bracket 30. In particular, the first operating member42 includes a first lever 42 a that is configured to be pivotally movedwith respect to the first master cylinder 44. A pivot pin 50 pivotallyconnects the first lever 42 a to the distal end portion 34 of thebracket 30. In the illustrated embodiment, the first operating member 42further includes a pair of gearshift operating parts 42 b and 42 c forperforming gear shifting operations of a gear changing device (notshown). Preferably, the gearshift operating parts 42 b and 42 c areelectrically connected to a gearshift control unit (not shown) that ismounted within a recess in the bracket 30.

The gearshift operating parts 42 b and 42 c are constructed as shown inU.S. Patent Application Publication No. 2009/0031841 A1 (assigned toShimano, Inc.). It will be apparent to those skilled in the bicyclefield that the gearshift operating parts 42 b and 42 c are not limitedto the illustrated structure and arrangement, but rather other suitablestructures and arrangements can be used as needed and/or desired. Thegearshift control unit (not shown) is a microcomputer that is located inthe bracket 30. However, the gearshift control unit can be remotelylocated if needed and/or desired. Since various electrical shiftingsystems are known in the bicycle field, the gearshift operating parts 42b and 42 c and the gearshift control unit will not be discussed hereinfor the sake of brevity. Alternatively, the first actuating device 14can be provided with a mechanical cable type shifting unit in which ashift cable is selectively pulled or released by the operation of theoperation of the mechanical cable type shifting unit. For example, themechanical cable type shifting unit could be mounted in the grippingportion 36 and one or more operating members can be provided on thefirst operating member 42 for operating the mechanical cable typeshifting unit.

Here, in the first embodiment, the first master cylinder 44 is formed byhydraulic unit 30 a of the bracket 30, and located within the grippingportion 36 of the bracket 30. In other words, the gripping portion 36 ofthe bracket 30 is partially formed by the hydraulic unit 30 b thatdefines a cylinder bore (interior hydraulic chamber) of the first mastercylinder 44. Alternatively, if needed and/or desired, it will beapparent to those skilled in the bicycle field that the first mastercylinder 44 can be integrally formed as a one-piece unit with the mainbody 30 a of the bracket 30. In other words, the bracket 30 can beconstructed as a one-piece member having the first master cylinder 44.

The bracket 30 further includes a connecting port 52 that fluidlyconnects the fluid reservoir 48 to the first master cylinder 44. In thisway, the fluid reservoir 48 supplies the hydraulic fluid (e.g., mineraloil) to the first master cylinder 44. The first master cylinder 44 has afirst fluid port 54. The first fluid port 54 is fluidly connected to thehydraulic chamber of the first master cylinder 44. The first hydraulicline 21 is fluidly connected to the first fluid port 54. In particular,for example, the first hydraulic line 21 is releasably connected to thefirst fluid port 54 of the bracket 30 by a conventional connector 58.

The first master piston 46 is movably arranged in the cylinder bore ofthe first master cylinder 44 in a reciprocal manner in response to anoperation of the first lever 42 a of the first operating member 42. Thefirst master piston 46 and an internal surface of the first mastercylinder 44 define a hydraulic chamber of the first actuating device 14.A biasing element 60 is disposed in the first master cylinder 44 forbiasing the first master piston 46 to a rest position or non-operatedposition. In the illustrated embodiment, the biasing element 60 is acoil compression spring (return spring) that also biases the first lever42 a of the first operating member 42 to its rest position (i.e., noexternal force applied to the first actuating device 14) as seen in FIG.2. As illustrated in FIGS. 2 and 3, the first lever 42 a of the firstoperating member 42 is operatively connected to the first master piston46 by a push rod 62. Preferably, the push rod 62 is connected to thefirst lever 42 a of the first operating member 42 with a reachadjustment connection (not illustrated) that adjusts the reach of thefirst lever 42 a. The reach adjustment connection between the push rod62 and the first lever 42 a can be, for example, substantially similarin construction to the reach adjustment connection that is disclosed inU.S. Patent Application Publication No. 2011/0147149 A1 (assigned toShimano, Inc.). Also preferably, the bracket 30 includes a piston endposition adjustment connection that controls relative positions of theoperating member 42 and the first master piston 48 in their restpositions with respect to the first master cylinder 44.

FIG. 3 shows the first lever 42 a of the first operating member 42pivoted about the pivot pin 50 from the rest position to a partiallyoperated position. Basically, the operation of the first lever 42 a ofthe first operating member 42 moves the push rod 62 which in turn pushesthe first master piston 46 within the cylinder bore of the first mastercylinder 44 against the biasing force of the biasing element 60. As theresult of this movement of the first master piston 46, the biasingelement 60 is compressed and the hydraulic fluid in the hydraulicchamber is forced out of the hydraulic chamber via the first fluid port54 into the first hydraulic line 21 to actuate the hydraulic operateddevice 18.

As best seen in FIG. 3, the fluid reservoir 48 is disposed within thedistal end portion 34 (i.e., the pommel portion) of the bracket 30 at alocation that is above the first master cylinder 44 while the firstactuating device 14 is in an installed position is in an installedposition on the drop handlebar 24 as seen in FIG. 1. Of course, it willbe apparent to those skilled in the bicycle field from this disclosurethat the fluid reservoir 48 is not limited to the illustrated location,but rather other suitable locations can also be used. In any case, thelocation of the fluid reservoir 48 is located above the first mastercylinder 44 while the first actuating device 14 is in an installedposition is in an installed position on the drop handlebar 24 as seen inFIG. 1. In the first embodiment, the fluid reservoir 48 includes aflexible diaphragm 64. The configuration, construction and function ofthe fluid reservoir 48 are well known in the bicycle field, and thus,will not be discussed in further detail herein.

Referring to FIGS. 1, 2 and 4, the second actuating device 16 will nowbe discussed. The second actuating device 16 is specifically designedfor use on the straight section 24 b of the drop handlebar 24. Unlikethe first actuating device 14, the second actuating device 16 onlyincludes a braking function. However, it will be apparent to thoseskilled in the bicycle field from this disclosure that a shiftingfunction could be added to the second actuating device 16 if neededand/or desired. The second actuating device 16 includes a base member 68having a handlebar clamp 70. The handlebar clamp 70 is a conventionaltube clamp that constitutes an example of a handlebar mounting member.Here, the handlebar clamp 70 is a hinged clamp. However, it will beapparent to those skilled in the bicycle field from this disclosure thatthe handlebar clamp 70 could be non-hinged clamp.

As seen FIGS. 1 and 4, the second actuating device 16 includes a secondoperating member 72, a second master cylinder 74 and a second masterpiston 76. In this first embodiment, the second actuating device 16 hasa fluid reservoir 78. Thus, in this first embodiment, the secondactuating device 16 is constructed as an open type hydraulic device. Theconstruction of the second actuating device 16 is disclosed in moredetail in U.S. Patent Application Publication No. 2011/0240425 A1(assigned to Shimano, Inc.). Basically, an operation of the secondoperating member 72 moves the second master piston 76 within the secondmaster cylinder 74 to cause displacement of hydraulic fluid from thesecond master cylinder 74 to actuate the hydraulic operated device 18via the switching device 20.

The second operating member 72 includes a second lever 72 a that isconfigured to be pivotally moved with respect to the second mastercylinder 74. In this first embodiment, the lever 72 a of the secondoperating member 72 extends a lateral direction in a state where thesecond actuating deceive 16 is mounted to the straight section 24 b ofthe drop handlebar 24. As seen in FIG. 1, a pivot pin 80 pivotallyconnects the second lever 72 a to the base member 68. While the secondoperating member 72 is illustrated as simply the second lever 72 a, itwill be apparent to those skilled in the bicycle field from thisdisclosure that the operating member 72 can include other parts and/orfeatures such as various adjustment mechanisms.

Here, in the first embodiment, the second master cylinder 74 is formedby the base member 68. In other words, the base member 68 forms ahydraulic cylinder housing that defines a cylinder bore (interiorhydraulic chamber) of the second master cylinder 74. Thus, the basemember 68 and the second master cylinder 74 are formed as an integralone-piece unit such that the base member 68 constitutes a cylinderhousing of the second master cylinder 74. It will be apparent to thoseskilled in the bicycle field that the second master cylinder 74 can bepart of a hydraulic unit that is detachable from the base member 68 ifneeded and/or desired.

The base member 68 further includes a connecting port 82 that fluidlyconnects the fluid reservoir 78 to the second master cylinder 74. Inthis way, the fluid reservoir 78 supplies the hydraulic fluid to thesecond master cylinder 74. The second master cylinder 74 has a secondfluid port 84. The second fluid port 84 is fluidly connected to thehydraulic chamber of the second master cylinder 74. The second hydraulicline 22 is fluidly connected to the second fluid port 84. In particular,for example, the second hydraulic line 22 is releasably connected tosecond fluid port 84 by a conventional connector 88.

The second master piston 76 is movably arranged in the cylinder bore ofthe second master cylinder 74 in a reciprocal manner in response to theoperation of the second lever 72 a of the second operating member 72.The second master piston 76 and an internal surface of the second mastercylinder 74 define a hydraulic chamber of the second actuating device16. A biasing element 90 is disposed in the second master cylinder 74for biasing the second master piston 76 to a rest position ornon-operated position. In the illustrated embodiment, the biasingelement 90 is a coil compression spring (return spring) that also biasesthe second lever 72 a of the second operating member 72 to its restposition (i.e., no external force applied to the second actuating device16) as seen in FIGS. 1 and 2. As illustrated in FIGS. 2 and 3, thesecond lever 72 a of the second operating member 72 is operativelyconnected to the second master piston 76 by a push rod 92. FIG. 4 showsthe second lever 72 a of the second operating member 72 pivoted aboutthe pivot pin 80 from the rest position to a partially operatedposition. Basically, the operation of the second lever 72 a of thesecond operating member 72 moves the push rod 92 which in turn pushesthe second master piston 76 within the cylinder bore of the secondmaster cylinder 74 against the biasing force of the biasing element 90.As the result of this movement of the second master piston 76, thebiasing element 90 is compressed and the hydraulic fluid in thehydraulic chamber is forced out of the hydraulic chamber via the secondfluid port 84 into the third hydraulic line 23 to actuate the hydraulicoperated device 18.

As best seen in FIG. 4, the fluid reservoir 78 is formed by the basemember 68 at a location that is above the second master cylinder 44while the second actuating device 16 is in an installed position on thestraight section 24 b of the drop handlebar 24 as seen in FIG. 1. Thus,the base member 68 and the fluid reservoir 78 are formed as an integralone-piece unit such that the base member 68 constitutes a reservoirhousing of the fluid reservoir 78. Of course, it will be apparent tothose skilled in the bicycle field from this disclosure that the fluidreservoir 78 is not limited to the illustrated location, but ratherother suitable locations can also be used. In any case, the location ofthe fluid reservoir 78 is located above the second master cylinder 74while the second actuating device 16 is in an installed position on thedrop handlebar 24 as seen in FIG. 1. In the first embodiment, the fluidreservoir 78 includes a flexible diaphragm 94. The configuration,construction and function of the fluid reservoir 78 are disclosed inmore detail in U.S. Patent Application Publication No. 2011/0240425 A1(assigned to Shimano, Inc.).

Here, in the first embodiment, the hydraulic operated device 18comprises a hydraulic braking device. More specifically, the hydraulicoperating device 18 comprises a disc brake caliper that engages a brakerotor (not shown) in a conventional manner for slowing the rotation orstopping a bicycle wheel (not shown) that is equipped with the brakerotor. As seen in FIGS. 1 and 2, the hydraulic operated device 18 has acaliper housing 95 that is mounted to a portion (not shown) of thebicycle 10. As seen in FIG. 2, the hydraulic operated device 18 includesa pair of slave cylinders 96 and a pair of slave pistons 98. The caliperhousing 95 defines the slave cylinders 96. The hydraulic operated device18 further includes a pair of brake pads 100 and a biasing member 102.The slave pistons 98 are movably arranged in the slave cylinders 96,respectively. While the hydraulic operated device 18 includes a pair ofmovable pistons, it will be apparent to those skilled in the bicyclefield from this disclosure that the hydraulic operated device 18 canhave one non-movable piston and only one movable piston if needed and/ordesired.

The slave pistons 98 are movably mounted in the caliper housing 95 in aconventional manner. The slave pistons 98 are biased away from eachother by the biasing member 102, which presses the brake pads 100outwardly against the slave pistons 98. The slave pistons 98 are movedtogether due to the pressure of the hydraulic fluid acting on the slavepistons 98 as a result of a user squeezing one of the first and secondlevers 42 a and 72 a of the first and second actuating devices 14 and 16that is fluidly connected to the caliper housing 95. The slave cylinders96 includes a slave fluid port 96 a that is fluidly connected to thefirst and second fluid ports 54 and 84 of the first and second mastercylinders 44 and 74. In particular, the third hydraulic line 23 isfluidly connected to the slave fluid port 96 a by a banjo bolt 103 thatscrews into the slave fluid port 96 a. An internal fluid communicationpassageway fluid connects the slave fluid port 96 a to each of the slavepistons 98. As a result, the operation of the first operating member 42moves the slave pistons 98, and the operation of the second operatingmember 72 moves the slave pistons 98.

Now the switching device 20 will be discussed in more detail. Basically,the switching device 20 selectively couples one of the first and secondmaster cylinders 44 and 74 to the hydraulic operated device 18. Theswitching device 20 includes a housing 104 having a first opening 104 a,a second opening 104 b and a third opening 104 c. The first opening 104a is fluidly connected to the first fluid port 54 of the first mastercylinder 44. The second opening 104 b is fluidly connected to the secondfluid port 84 the second master cylinder 74. The third opening 104 c isfluidly connected to the slave fluid port 96 a of the slave cylinders96. The switching device 20 further includes a movable member 106 thatis movably mounted in the housing 104 to block the second opening 104 bin response to the operation of the first operating member 42 and toblock the first opening 104 a in response to the operation of the secondoperating member 72. In particular, the movable member 106 is pivotallycoupled to the housing 104, and pivots in response to the pressure fromthe hydraulic fluid from the operation of the first and second operatingmembers 42 and 72. Accordingly, when the first lever 42 a is operated,the movable member 106 blocks the second opening 104 b so that thehydraulic fluid flows through the third opening 104 c into the thirdhydraulic line 23, and does not flow into the second hydraulic line 22.Likewise, when the second lever 72 a is operated, the movable member 106blocks the first opening 104 a so that the hydraulic fluid flows throughthe third opening 104 c into the third hydraulic line 23, and does notflow into the first hydraulic line 21.

In the bicycle hydraulic operating system 12, the first and secondactuating devices 14 and 16 have the fluid reservoirs 48 and 78respectively such that the first and second actuating devices 14 and 16are both open type hydraulic devices. However, the bicycle hydraulicoperating system 12 can be constructed such that only at least one ofthe first and second actuating devices has a fluid reservoir. In otherwords, the bicycle hydraulic operating system 12 can be constructed suchthat one of the first and second actuating devices is an open typehydraulic device that has a fluid reservoir while the other of the firstand second actuating devices is a closed type hydraulic device that hasno reservoir.

Basically, in summary, the operation of the first lever 42 a or thesecond lever 72 a causes displacement of the hydraulic fluid from thefirst master cylinder 44 or the second master cylinder 74 to theswitching device 20. The movable member 106 blocks one of the first andsecond openings 104 a and 104 b, depending on which one of the first andsecond levers 42 a and 72 a is operated so that the hydraulic fluidflows through the third opening 104 c into the third hydraulic line 23.The third hydraulic line 23 is connected to the slave fluid port 96 asuch that the hydraulic fluid being forced through the third hydraulicline 23 moves the slave pistons 98 in the slave cylinders 96. Inaccordance with movement of the slave cylinders, the brake pads 100 comeinto contact with the brake rotor for applying frictional resistance andcausing the bicycle to slow down or stop. Of course, the bicyclehydraulic operating system 12 is not limited to being used with ahydraulic brake system.

With the bicycle hydraulic operating system 12, it will be apparent tothose skilled in the bicycle field that the first and second actuatingdevices 14 and 16 can be configured with either identical actuationratios or different actuation ratios. As used herein, the term actuationratio refers to a ratio of an input change (i.e., a stroke or movementamount of the operating member) to an output effect (i.e., a movementamount of the brake pads). Here, the output effect for each of the firstand second actuating devices 14 and 16 is the amount of the hydraulicfluid that is outputted for a given amount of movement of the operatedmember 18. Preferably, the first actuating device 14 has a firstactuation ratio, and the second actuating device 16 has a secondactuation ratio that is larger than the first actuation ratio such thatmore the hydraulic fluid is displaced by the operation of the secondoperating member 72 than by the operation of the first operating member42 for an identical stroke. In other words, the first actuating device14 is configured to displace the hydraulic fluid with a first amount asthe first lever 42 a is pivoted with a first stroke. The secondactuating device 16 is configured to displace the hydraulic fluid with asecond amount differing from the first amount as the second lever 72 ais pivoted with a second stroke being same as the first stroke.

Referring now to FIG. 5, a bicycle hydraulic operating system 112 inaccordance with a second embodiment will now be discussed. In view ofthe similarity between the first and second embodiments, the bicyclehydraulic operating system 112 will only be briefly discussed for thesake of brevity. Moreover, the parts of the second embodiment, which areidentical to the corresponding parts of the first embodiment, will begiven the same reference numbers as in the first embodiment.

The bicycle hydraulic operating system 112 basically comprises the firstactuating device 14 of the first embodiment, a second actuating device116 and the hydraulic operated device 18 of the first embodiment. Here,in the second embodiment, the bicycle hydraulic operating system 112further comprises the switching device 20 of the first embodiment.Similar to the first embodiment, the switching device 20 selectivelycouples one of the first and second actuating devices 14 and 116 to thehydraulic operated device 18. In this way, the rider can actuate thehydraulic operated device 18 using either one of the first and secondactuating devices 14 and 116. Similar to the first embodiment, the firstand second actuating devices 14 and 116 are fluidly connected to theswitching device 20 by the first and second hydraulic lines 21 and 22,while the switching device 20 is fluidly connected to the hydraulicoperated device 18 by the third hydraulic line 23.

The only difference between the first and second embodiments is that thesecond embodiment uses the second actuating device 116 instead of thesecond actuating device 16. The second actuating device 116 is identicalto the second actuating device 16 of the first embodiment, except thatthe second actuating device 116 does not have a fluid reservoir. Inother words, the second embodiment, the first actuating device 14 is anopen type hydraulic device, while the second actuating device 116 is aclosed type hydraulic device that has no fluid reservoir. Alternatively,the first actuating device 14 can be constructed without a fluidreservoir and used with the second actuating device 16. In other words,one of the first and second actuating devices is an open type hydraulicdevice that has a fluid reservoir while the other of the first andsecond actuating devices is a closed type hydraulic device that has noreservoir.

Referring now to FIGS. 6 to 9, a bicycle hydraulic operating system 212in accordance with a third embodiment will now be discussed. In view ofthe similarity between the bicycle hydraulic operating system 212 andthe prior embodiments, the bicycle hydraulic operating system 212 willonly be briefly discussed for the sake of brevity. Moreover, the partsof the third embodiment, which are identical to the corresponding partsof the first embodiment, will be given the same reference numbers as inthe first embodiment.

The bicycle hydraulic operating system 212 basically comprises the firstactuating device 14 of the first embodiment, a second actuating device216 and the hydraulic operated device 18 of the first embodiment. In thethird embodiment, the second actuating device 216 has no fluid reservoirsimilar to the second actuating device 116 of the second embodiment.Thus, the second actuating device 216 is constructed as a closed typehydraulic device. The first hydraulic line 21 is fluidly connected tothe second actuating device 216 such that the fluid reservoir 48 of thefirst actuating device 14 also acts as the fluid reservoir for thesecond actuating device 216. The third hydraulic line 23 fluidlyconnects the second actuating device 216 to the hydraulic operateddevice 18, and thus, also fluidly connects the first actuating device 14to the hydraulic operated device 18. Thus, similar to the priorembodiments, the rider can actuate the hydraulic operated device 18using either one of the first and second actuating devices 14 and 216.

As seen in FIGS. 6 and 7, the second actuating device 216 includes abase member 268 having an integrated handlebar clamp 270. The secondactuating device 216 further includes a second operating member 272, asecond master cylinder 274 and a second master piston 276. A pivot pin280 pivotally connects the second operating member 272 to the basemember 268. As seen in FIGS. 8 and 9, the second actuating device 216further includes a connecting port 281. The connecting port 218selectively and fluidly connects the first fluid port 54 of the firstactuating device 14 to the slave fluid port 96 a of the hydraulicoperated device 18 in accordance with position of the second masterpiston 276 of the second actuating device 216. More specifically, theconnecting port 281 comprises a first portion 281 a, a second portion281 b and a third portion 281 c. The third portion 281 c is configuredto attach the first hydraulic line 21. The first and second portions 281a and 281 b extend from the third portion 281 c to the hydraulic chamberof the second master cylinder 274 for supplying hydraulic fluid from thefirst master cylinder 44 of the first actuating device 14 to thehydraulic chamber of the second master cylinder 274. In other words, thefirst and second portions 281 a and 281 b receive hydraulic fluid fromthe first master cylinder 44 of the first actuating device 14. Inparticular, the first portion 281 a selectively and fluidly connects thefirst fluid port 54 to the slave fluid port 96 a in accordance withposition of the second master piston 276. While the second portion 281 bis in fluid communication with a space S between an outer surface of thesecond master piston 276 and an inner surface of the second mastercylinder 274. The second master cylinder 274 also has a second fluidport 284. The third hydraulic line 23 is fluidly connected to the secondfluid port 284. The second actuating device 216 is identical to thesecond actuating device 16 of the first embodiment, except that thesecond actuating device 216 does not have a fluid reservoir and thefirst master cylinder 44 of the first actuating device 14 is fluidlyconnected to the second master cylinder 274 of the second actuatingdevice 216. Thus, in this third embodiment, the second actuating device216 is effectively an open type hydraulic device in that the fluidreservoir 78 supplies hydraulic fluid to the hydraulic chamber of thesecond master cylinder 274. In particular, the first fluid port 54 ofthe first actuating device 14 is fluidly connected to the second mastercylinder 274 of the second actuating device 216 at a point upstream ofthe second fluid port 284 with respect to a flow of hydraulic fluidtowards the hydraulic operated device 18. When the first and secondactuating devices 14 and 216 are mounted on the handlebar 24, the fluidreservoir 78 is located above the second master cylinder 274.

As seen in FIG. 8, the second master piston 276 is in a rest position ora non-operated position in which the first portion 281 a of theconnecting port 281 is open (i.e., in fluid communication with thehydraulic chamber of the second master cylinder 274) while the secondoperating member 272 is in a rest position or a non-operated position.As seen in FIG. 9, the second master piston 276 is in an operatedposition in which the first portion 281 a of the connecting port 281 isclosed (i.e., not in fluid communication with the hydraulic chamber ofthe second master cylinder 274) while the second operating member 272 isin the operated position. Thus, the operation of the second operatingmember 272 moves the second master piston 276 to block fluidcommunication between the first master cylinder 44 of the firstactuating device 14 and the second master cylinder 274 of the secondactuating device 216. However, when the second operating member 272 isin the rest position, the hydraulic fluid from the first master cylinder44 can be forced through the second master cylinder 274 to actuate thehydraulic operated device 18. Also as a result of the second portion 281b of the connecting port 281 being in fluid communication with a spaceS, the hydraulic fluid from the first actuating device 14 lubricants theouter surface of the second master piston 276 and the inner surface ofthe second master cylinder 274.

In the second actuating device 216, a biasing element 290 is disposed inthe second master cylinder 274 for biasing the second master piston 276to the rest position. In the illustrated embodiment, the biasing element290 is a coil compression spring (return spring) that also biases thesecond operating member 272 to its rest position (i.e., no externalforce applied to the second actuating device 216) as seen in FIGS. 7 and8.

As illustrated in FIGS. 7 to 9, the second operating member 272 isoperatively connected to the second master piston 276 by a push rod 292.Basically, an operation of the second operating member 272 moves thepush rod 292 which in turn pushes the second master piston 276 withinthe cylinder bore of the second master cylinder 274 against the biasingforce of the biasing element 290. As the result of this movement of thesecond master piston 276, the biasing element 290 is compressed and thehydraulic fluid is forced out of the hydraulic chamber via the secondfluid port 284 into the third hydraulic line 23 to actuate the hydraulicoperated device 18.

Referring now to FIG. 10, a bicycle hydraulic operating system 312 inaccordance with a fourth embodiment will now be discussed. The bicyclehydraulic operating system 312 basically comprises a first actuatingdevice 314, the second actuating device 216 of the third embodiment andthe hydraulic operated device 18 of the prior embodiments. The onlydifference between the fourth and third embodiments is that the fourthembodiment uses the first actuating device 314 instead of the firstactuating device 14. The first actuating device 314 is identical to thefirst actuating device 14 of the first embodiment, except that the firstactuating device 314 does not have a fluid reservoir. Thus, the firstactuating device 14 includes a drop handlebar bracket 330 that isidentical to the drop handlebar bracket 30, except that the drophandlebar bracket 330 does not have a fluid reservoir. Similar to thethird embodiment, the rider can actuate the hydraulic operated device 18using either one of the first and second actuating devices 314 and 216.Similar to the third embodiment, the first and second actuating devices314 and 216 are fluidly connected by the first hydraulic line 21, whilethe second actuating device 216 is fluidly connected to the hydraulicoperated device 18 by the third hydraulic line 23.

In view of the similarity between the fourth embodiment and the priorembodiments, the bicycle hydraulic operating system 312 will only bebriefly discussed for the sake of brevity. Moreover, the parts of theprior embodiments, which are identical to the corresponding parts of thefirst embodiment, will be given the same reference numbers as in theprior embodiments.

Referring now to FIGS. 11 to 14, a bicycle hydraulic operating system412 in accordance with a fifth embodiment will now be discussed. In viewof the similarity between the bicycle hydraulic operating system 412 andthe prior embodiments, the bicycle hydraulic operating system 412 willonly be briefly discussed for the sake of brevity. Moreover, the partsof the fifth embodiment, which are identical to the corresponding partsof the prior embodiments, will be given the same reference numbers as inthe prior embodiments.

The bicycle hydraulic operating system 412 basically comprises the firstactuating device 14 or 314 of the first or fourth embodiment, a secondactuating device 416 and the hydraulic operated device 18 of the priorembodiments. In the fifth embodiment, similar to the second, third andfourth embodiments, the second actuating device 416 has no fluidreservoir. Thus, the second actuating device 416 is constructed as aclosed type hydraulic device. The first hydraulic line 21 is fluidlyconnected to the second actuating device 416 such that the firstactuating device 14 or 314 acts as the fluid reservoir for the secondactuating device 416. The third hydraulic line 23 fluidly connects thesecond actuating device 416 to the hydraulic operated device 18, andthus, also fluidly connects the first actuating device 14 or 314 to thehydraulic operated device 18. Thus, similar to the first embodiment, therider can actuate the hydraulic operated device 18 using either one ofthe first and second actuating devices 14 and 416.

The second actuating device 416 is identical to the second actuatingdevice 216, except as discussed below. In view of the similarity betweenthe second actuating devices 216 and 416, the second actuating device416 will only be partially illustrated and briefly discussed for thesake of brevity.

As seen in FIG. 11, the second actuating device 416 includes a basemember 468 having an integrated handlebar clamp 470. The secondactuating device 416 further includes a second operating member 472, asecond master cylinder 474 and a second master piston 476. A pivot pin480 pivotally connects the second operating member 472 to the basemember 468. As seen in FIGS. 12 to 14, the second actuating device 416further includes a connecting port 482. The connecting port 482comprises a first diameter portion 482 a configured to attach the firsthydraulic line, and a second diameter portion 482 b extends from thefirst diameter portion 482 a. The second diameter portion 482 b iscoughed to have smaller diameter than the first diameter portion 482 a.The second diameter portion 482 b is provided for supplying hydraulicfluid from the first actuating device 14 or 314 to the hydraulic chamberof the second master cylinder 474. In other words, the connecting port482 receives hydraulic fluid from the first actuating device 14 or 314.The second master cylinder 474 also has a second fluid port 484. Thethird hydraulic line 23 is fluidly connected to the second fluid port484. When the first actuating device 14 or 314 and the second actuatingdevice 416 are mounted on the handlebar 24, the first master cylinder ofthe first actuating device 14 or 314 is located above the second mastercylinder 474.

In the second actuating device 416, a biasing element 490 is disposed inthe second master cylinder 474 for biasing the second master piston 476to the rest position. In the illustrated embodiment, the biasing element490 is a coil compression spring (return spring) that also biases thesecond operating member 472 to its rest position (i.e., no externalforce applied to the second actuating device 416) as seen in FIGS. 11and 12.

In this fifth embodiment, the second actuating device 416 is effectivelyan open system in that the first actuating device 14 or 314 supplieshydraulic fluid to the hydraulic chamber of the second master cylinder474. In particular, the first master cylinder of the first actuatingdevice 14 or 314 is fluidly connected to the second master cylinder 474of the second actuating device 416 at a point upstream of the secondfluid port 484 of the second actuating device 416 with respect to a flowof hydraulic fluid towards the hydraulic operated device 18.

As illustrated in FIG. 12, the second actuating device 416 furtherincludes a push rod 492. The second operating member 472 is operativelyconnected to the second master piston 476 by the push rod 492. The pushrod 492 has a first end 492 a connected to the second operating member472 and a second end 492 b coupled to the second master piston 476. Thesecond master piston 476 has a fluid passage 476 a that fluidly connectsthe connecting port 482 to the second fluid port 484 through the secondmaster piston 476 while the second operating member 472 is in the restposition as seen in FIG. 12. The fluid passage 476 a of the secondmaster piston 476 is selectively closed by the push rod in response toan operation of the second operating member 472. In more detail, as seenin FIGS. 13 and 14, the second end 492 b of the push rod 492 is slidablyarranged relative to the second master piston 476 during an initialstroke amount of the second operating member 472 to close the fluidpassage 476 a of the second master piston 476 (see, FIG. 13) and thenmove the second master piston 476 as the second operating member 472 ismoved further past the initial stroke amount from the non-operatedposition (see, FIG. 14). In this way, the hydraulic fluid from the firstactuating device 14 or 314 lubricates the second master piston 476 andsupplies hydraulic fluid to the second master cylinder 474. Thus, thebasic operation of the second actuating device 416 is similar to theoperation of the second actuating device 216 of the third and fourthembodiments.

In understanding the scope of the present invention, the term“comprising” and its derivatives, as used herein, are intended to beopen ended terms that specify the presence of the stated features,elements, components, groups, integers, and/or steps, but do not excludethe presence of other unstated features, elements, components, groups,integers and/or steps. The foregoing also applies to words havingsimilar meanings such as the terms, “including”, “having” and theirderivatives. Also, the terms “part,” “section,” “portion,” “member” or“element” when used in the singular can have the dual meaning of asingle part or a plurality of parts unless otherwise stated.

As used herein, the following directional terms “frame facing side”,“non-frame facing side”, “forward”, “rearward”, “front”, “rear”, “up”,“down”, “above”, “below”, “upward”, “downward”, “top”, “bottom”, “side”,“vertical”, “horizontal”, “perpendicular” and “transverse” as well asany other similar directional terms refer to those directions of abicycle in an upright, riding position and equipped with the hydraulicoperating system. Accordingly, these directional terms, as utilized todescribe the hydraulic operating system should be interpreted relativeto a bicycle in an upright riding position on a horizontal surface andthat is equipped with the hydraulic operating system. The terms “left”and “right” are used to indicate the “right” when referencing from theright side as viewed from the rear of the bicycle, and the “left” whenreferencing from the left side as viewed from the rear of the bicycle.

Also it will be understood that although the terms “first” and “second”may be used herein to describe various components these componentsshould not be limited by these terms. These terms are only used todistinguish one component from another. Thus, for example, a firstcomponent discussed above could be termed a second component andvice-a-versa without departing from the teachings of the presentinvention. The term “attached” or “attaching”, as used herein,encompasses configurations in which an element is directly secured toanother element by affixing the element directly to the other element;configurations in which the element is indirectly secured to the otherelement by affixing the element to the intermediate member(s) which inturn are affixed to the other element; and configurations in which oneelement is integral with another element, i.e. one element isessentially part of the other element. This definition also applies towords of similar meaning, for example, “joined”, “connected”, “coupled”,“mounted”, “bonded”, “fixed” and their derivatives. Finally, terms ofdegree such as “substantially”, “about” and “approximately” as usedherein mean an amount of deviation of the modified term such that theend result is not significantly changed.

While only selected embodiments have been chosen to illustrate thepresent invention, it will be apparent to those skilled in the art fromthis disclosure that various changes and modifications can be madeherein without departing from the scope of the invention as defined inthe appended claims. For example, unless specifically stated otherwise,the size, shape, location or orientation of the various components canbe changed as needed and/or desired so long as the changes do notsubstantially affect their intended function. Unless specifically statedotherwise, components that are shown directly connected or contactingeach other can have intermediate structures disposed between them solong as the changes do not substantially affect their intended function.The functions of one element can be performed by two, and vice versaunless specifically stated otherwise. The structures and functions ofone embodiment can be adopted in another embodiment. It is not necessaryfor all advantages to be present in a particular embodiment at the sametime. Every feature which is unique from the prior art, alone or incombination with other features, also should be considered a separatedescription of further inventions by the applicant, including thestructural and/or functional concepts embodied by such feature(s). Thus,the foregoing descriptions of the embodiments according to the presentinvention are provided for illustration only, and not for the purpose oflimiting the invention as defined by the appended claims and theirequivalents.

1. A bicycle hydraulic operating system comprising: a first actuatingdevice including a first operating member, a first master cylinderhaving a first fluid port and a first master piston movably arranged inthe first master cylinder in response to an operation of the firstoperating member, a second actuating device including a second operatingmember, a second master cylinder having a second fluid port and a secondmaster piston movably arranged in the second master cylinder in responseto an operation of the second operating member; and a hydraulic operateddevice including a slave cylinder and a slave piston movably arranged inthe slave cylinder, the slave cylinder having a slave fluid port fluidlyconnected to the first and second fluid ports of the first and secondmaster cylinders such that the operation of the first operating membermoves the slave piston and such that the operation of the secondoperating member moves the slave piston.
 2. The bicycle hydraulicoperating system according to claim 1, wherein at least one of the firstand second actuating devices has a fluid reservoir.
 3. The bicyclehydraulic operating system according to claim 1, wherein one of thefirst and second actuating devices has a fluid reservoir and the otherof the first and second actuating devices has no fluid reservoir.
 4. Thebicycle hydraulic operating system according to claim 1, wherein thefirst operating member includes a first lever, the first actuatingdevice is configured to displace hydraulic fluid with a first amount asthe first lever is pivoted with a first stroke, the second operatingmember includes a second lever, and the second actuating device isconfigured to displace hydraulic fluid with a second amount differingfrom the first amount as the second lever is pivoted with a secondstroke being same as the first stroke.
 5. The bicycle hydraulicoperating system according to claim 1, further comprising a switchingdevice selectively coupling one of the first and second master cylindersto the hydraulic operated device.
 6. The bicycle hydraulic operatingsystem according to claim 5, wherein at least one of the first andsecond actuating devices has a fluid reservoir.
 7. The bicycle hydraulicoperating system according to claim 5, wherein the switching deviceincludes a housing having a first opening fluidly connected to the firstfluid port of the first master cylinder, a second opening fluidlyconnected to the second fluid port of the second master cylinder and athird opening fluidly connected to the slave fluid port of the slavecylinder, and the switching device further includes a movable membermovably mounted in the housing to block the second opening in responseto the operation of the first operating member and to block the firstopening in response to the operation of the second operating member. 8.The bicycle hydraulic operating system according to claim 1, wherein thesecond actuating device has no fluid reservoir, and the first fluid portof the first actuating device is fluidly connected to the second mastercylinder of the second actuating device at a point upstream of thesecond fluid port with respect to a flow of hydraulic fluid towards thehydraulic operated device.
 9. The bicycle hydraulic operating systemaccording to claim 8, wherein the second master cylinder of the secondactuating device further includes a connecting port, and the connectingport selectively and fluidly connects the first fluid port of the firstactuating device to the slave fluid port of the hydraulic operateddevice in accordance with a position of the second master piston of thesecond actuating device.
 10. The bicycle hydraulic operating systemaccording to claim 9, wherein the connecting port comprises a firstportion and a second portion, the first portion selectively and fluidlyconnects the first fluid port to the slave fluid port in accordance withthe position of the second master piston, and the second portion is influid communication with a space between an outer surface of the secondmaster piston and an inner surface of the second master cylinder. 11.The bicycle hydraulic operating system according to claim 8, wherein thesecond actuating device further includes a connecting port and a pushrod, the push rod operatively connects the second operating member tothe second master piston, the second master piston has a fluid passagethat fluidly connects the connecting port to the second fluid portthrough the second master piston and is selectively blocked by the pushrod in response to the operation of the second operating member.
 12. Thebicycle hydraulic operating system according to claim 1, wherein thefirst actuating device includes a bracket having a proximal end portion,a distal end portion and a gripping portion that is arranged between theproximal end portion and the distal end portion, and a securing memberthat is provided on the proximal end portion of the bracket for securingthe bracket to a handlebar, the first operating member is pivotallyattached to the distal end portion.
 13. The bicycle hydraulic operatingsystem according to claim 12, wherein the second actuating device isconfigured such that the second operating member extends in a lateraldirection in a state where the second actuating deceive is mounted tothe handlebar.
 14. The bicycle hydraulic operating system according toclaim 1, wherein the hydraulic operated device comprises a hydraulicbraking device.
 15. The bicycle hydraulic operating system according toclaim 14, wherein the hydraulic operated device comprises a hydraulicdisc brake caliper.